Testing Results and Evaluation

Designed by Nghia (Wilson) Ly, Caleb Mayer, Daria Frame

Test 1

Procedure

1. Information about EDD and the bike are provided, along with the idea behind the bike relating to a RipStik.
2. A demonstration is given as to how to properly ride the bike, along with side commentary about the motion and how to achieve it.
3. Volunteers get on the bike and try to ride it. Each time, advice and tips are provided to try and get them operating the bike as well as possible. Each volunteer can spend as much time as needed, within the class period, to get a hang of the bike.
4. Testers then complete the corresponding feedback form. This is where their age, weight and height are provided.

Data

Each rider was asked to rate their ability in using the bike. This is what they gave us.

Results

The levels of skill users felt they had in using the bike varied a lot, but consideration needs to be given in the amount of time they had to ‘master’ the skill, which was not enough for some. However, there was also a group of users who took to the bike naturally and, given more time, would be moving more consistently and smoother. On the forms and in person, people were pretty specific in what they felt needed improvement, for example, how the handle bars moved when pressure was placed on them. However, the majority agreed that the measurements of the bike felt comfortable to them as they rode. The aspect they found most difficult was, of course, getting the right twisting of the back wheel synchronized with the motion of the front wheel. However, as mentioned earlier, many of them showed skill that was capable of riding the bike very well if given more time. Finally, during the testing, most of the users were really excited and interested about the bike and riding it, even if it was a really difficult skill for them to perform, and since bringing the bike to school, it has drawn attention and interest from all levels of the school.

Design Improvements

- Find a handlebar/shaft that better fits the bike so that riders can put pressure here without the worry that it will move forward or backward. This would also make it more safe.
- Incorporate a braking system to help safety. The lack of breaks was also mentioned in passing.
- Round off the back wheel cage so that, if the rider's leg hits it, the impact is felt less. The only reason this was not initially done was because we did not have access to the right tools.

Test 2

Procedure

1. Bike is placed in an upright, stable position.
2. The distance between the bottom edge of the footrests and the floor is measured.
3. Weights are hung from the bike at the seat. This can be done using bags and/or fishing wire.
4. Leave the bike like this for several hours and take periodic measurements of how far the footrests are from the floor.
5. At the end of the time, all of the weights are taken off and the distance between the footrests and the floor are measured and recorded.

Results

After each round of weights, there was no deformation in the footrests. The titanium held up even under 200Lbs of weight applied at the seat. This means the bike will definitely be able to hold kids in the 5-10 year old age range.

Test 3

Procedure

1. The plastic box lid is placed on the ground, with the curved edges facing up.
2. Two pieces of grip tape are placed vertically from the weight also resting on the lid, about an inch apart from each other.
3. A string is attached to the weight.
4. The other side to of the string needs to be attached to a spring scale.
5. The force needed to pull the weight across the smooth plastic surface is measured and recorded. This only happens once for each weight.
6. Pull the other end of the force pulley, horizontally. Determine and record the amount of force it takes to start the movement of the weight across the grip tape. Repeat each 10 times and find the average.
  1. If the test fails, two other grip tapes will go through the same test. From this, a better material can be determined.
7. Each weight is also pulled, at the end, on the grip tape, without the lid held down. This tests whether or not the tape can move the whole system.

Data

10 tests are performed for each weight value, however many of the points are the same.

Results

The results of this test were meant to be quantitative, as they were, but we also received qualitative results from observations made throughout the test. As each of the different weights were drug across the traction tape, they never appeared to slip and then catch before they were completely cleared of the tape; there was a consistent frictional resistance throughout the pull along the length of the tape, which meant maximum static force was only hit once in the process. Also, the results are useable because for each weight, the forces recorded after each test are consistent in amount, only ever a couple of newton's off from the others. Finally, we noticed that the tape held up visually and consistently throughout the testing and never needed to be replaced. While some of the forces recorded are lower than what would be produced by a child, all ranges needed to be tested. The maximum weight tested was proportional to the force that would be applied by the user, however the tests were more successful when the tape what placed closer together so that it was wider overall.

Design Improvements

- If it does not sacrifice safety, the footrests could be longer. This allows for more room for the foot to slip, if it does, and more area for the foot to hold onto when applying force while riding.

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